Linux: Reset iptables firewall rules


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Create a shell script (iptables_flush.sh) and copy paste the following lines:

#!/bin/sh
echo "Flushing iptables rules..."
sleep 1
iptables -F
iptables -X
iptables -t nat -F
iptables -t nat -X
iptables -t mangle -F
iptables -t mangle -X
iptables -P INPUT ACCEPT
iptables -P FORWARD ACCEPT
iptables -P OUTPUT ACCEPT

Make the file executable
chmod +x iptables_flush.sh
and run the script:
./iptables_flush.sh

4 thoughts on “Linux: Reset iptables firewall rules


  1. Warning: Use of undefined constant user_level - assumed 'user_level' (this will throw an Error in a future version of PHP) in /homepages/3/d98111892/htdocs/insanelabs/htdocs/wp-content/plugins/ultimate-google-analytics/ultimate_ga.php on line 524
    Wladimir Tavares says:

    Warning: Use of undefined constant user_level - assumed 'user_level' (this will throw an Error in a future version of PHP) in /homepages/3/d98111892/htdocs/insanelabs/htdocs/wp-content/plugins/ultimate-google-analytics/ultimate_ga.php on line 524

    There rules will lock down the machine and if you are connecting from a remote ssh session you wont connect.

    I’d recommend these rules

    # iptables -P INPUT ACCEPT
    # iptables -F
    # iptables -A INPUT -i lo -j ACCEPT
    # iptables -A INPUT -m state –state ESTABLISHED,RELATED -j ACCEPT
    # iptables -A INPUT -p tcp –dport 22 -j ACCEPT
    # iptables -P INPUT DROP
    # iptables -P FORWARD DROP
    # iptables -P OUTPUT ACCEPT
    # iptables -L -v

  2. Pingback:
    Warning: Use of undefined constant user_level - assumed 'user_level' (this will throw an Error in a future version of PHP) in /homepages/3/d98111892/htdocs/insanelabs/htdocs/wp-content/plugins/ultimate-google-analytics/ultimate_ga.php on line 524
    Reset iptables Rules – shkschneider's Blog
  3. Pingback:
    Warning: Use of undefined constant user_level - assumed 'user_level' (this will throw an Error in a future version of PHP) in /homepages/3/d98111892/htdocs/insanelabs/htdocs/wp-content/plugins/ultimate-google-analytics/ultimate_ga.php on line 524
    Notizbox » Blog Archiv » iptables Regeln zurücksetzen

  4. Warning: Use of undefined constant user_level - assumed 'user_level' (this will throw an Error in a future version of PHP) in /homepages/3/d98111892/htdocs/insanelabs/htdocs/wp-content/plugins/ultimate-google-analytics/ultimate_ga.php on line 524
    Mokhtar Ebrahim says:

    Warning: Use of undefined constant user_level - assumed 'user_level' (this will throw an Error in a future version of PHP) in /homepages/3/d98111892/htdocs/insanelabs/htdocs/wp-content/plugins/ultimate-google-analytics/ultimate_ga.php on line 524

    Flushing iptables rules when I get lost which rule runs first 🙂

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